Semiconductor device having grooved leads to confine solder wicking

A semiconductor and lead technology, applied in the direction of semiconductor devices, semiconductor/solid-state device manufacturing, semiconductor/solid-state device components, etc., can solve problems such as difficulty in containing solder wicking

Active Publication Date: 2010-12-15
TEXAS INSTR INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Then, the requirement to use lead-free solder pushes the reflow temperature range to around 260°C, making it more difficult to contain solder wicking

Method used

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  • Semiconductor device having grooved leads to confine solder wicking
  • Semiconductor device having grooved leads to confine solder wicking
  • Semiconductor device having grooved leads to confine solder wicking

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0022] figure 1 An exemplary embodiment of the invention is illustrated. figure 1 Depicts a portion of a semiconductor device (generally designated 100 ) belonging to the surface mount product family. These devices have an insulating package 120 with a protruding metal segment 101 outside the package 120 and thus called the outer segment 101 . The outer segment is shaped and formed to attach to the surface of a substrate or board 190 using solder 110; figure 1 The shape illustrated in is often referred to as the "gull wing" shape. After surface mount device solder attachment to the substrate, it is easy to visually inspect all solder reflow sites to confirm defect-free attachment and contact - a major reason why surface mount devices are so popular in the semiconductor industry.

[0023] The metal portion of device 100 includes: pad 102 for firmly positioning semiconductor chip 103 ; metal outer segment 101 ; and metal segment 104 located inside package 120 ("inner" segment...

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PUM

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Abstract

A packaged surface-mount semiconductor device (100) has the outer, un-encapsulated lead segments structured in five adjoining portions: The first portion (141) protrudes from the encapsulation (120) about horizontally; the second portion (142) forms a convex bend downwardly; the third portion (143) is approximately straight downwardly; the fourth portion (144) forms a concave bend upwardly; and the fifth portion (145) is straight horizontally. Each segment has across the width a first groove in the third portion, either on the bottom surface or on the top surface. Preferably, the groove is about 2 leadframe thicknesses vertically over the bottom surface of the fifth lead portion. When stamped, the groove may have an angular outline about 5 and 50 [mu]m deep; when etched, the groove may have an approximately semicircular outline about 50 to 125 [mu]m deep. A second groove may be located in the second segment portion; a third groove may be located in the transition region from the thirdto the fourth segment portions.

Description

technical field [0001] The present invention relates generally to the field of semiconductor devices and processes, and more particularly to surface mount devices having leads with grooves to limit solder wicking. Background technique [0002] The lead frame of a semiconductor device provides stable support pads for firmly positioning a semiconductor chip, typically an integrated circuit (IC) chip, within a package. It has become common practice to fabricate monolithic lead frames from thin (approximately 100 [mu]m to 250 [mu]m) metal sheets. For reasons of ease of manufacture, the usual starting metals of choice are copper, copper alloys, iron-nickel alloys (such as the so-called "alloy 42") and aluminum. The desired shape of the lead frame is molded or etched from the original sheet. [0003] In addition to the chip pad, the lead frame also provides a plurality of conductive segments to bring various electrical conductors in close proximity to the chip. The remaining ga...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L21/60
CPCH01L2924/01046H05K2201/1084H01L24/48H01L2924/01079H05K3/3426H01L2224/48465H01L2224/32245H01L2224/48247H01L2924/14H01L23/49548H01L2924/01029H01L23/49555H01L2224/48091H01L2924/01013H01L2224/73265H05K2201/10848H05K2201/10689H01L2224/451H01L2224/45144H01L24/45H01L2924/181H01L2224/05554Y02P70/50H01L2924/00014H01L2924/00H01L2924/00015H01L2924/00012
Inventor 约翰·特尔坎普
Owner TEXAS INSTR INC
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